Display apparatus having grooved terminals and method of manufacturing the same

ABSTRACT

A display apparatus includes a display panel having a display substrate on which a plurality of pad terminals is disposed, and a driving unit having a plurality of driving terminals electrically connected to the plurality of pad terminals. Each of the plurality of pad terminals includes a stepped groove that faces a corresponding driving terminal of the plurality of driving terminals or each of the plurality of pad terminals includes an opening hole that faces the corresponding driving terminal of the plurality of driving terminals.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of co-pending U.S. patent applicationSer. No. 16/267,003, filed on Feb. 4, 2019, which is a Division of U.S.patent application Ser. No. 15/362,082, filed on Nov. 28, 2016, whichclaims priority to, and the benefit of, Korean Patent Application No.10-2016-0077556, filed on Jun. 21, 2016, in the Korean IntellectualProperty Office, the disclosures of which are incorporated by referenceherein in their entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention relate to displayapparatuses, and more particularly, to display apparatuses havinggrooved terminals and methods of manufacturing the same.

DISCUSSION OF THE RELATED ART

Display apparatuses can be found within all sorts of devices such assmartphones, laptop computers, digital cameras, camcorders, portableinformation terminal devices, notebooks, tablet personal computers(PCs), and other such mobile devices. Display apparatuses are also foundin stationary electronic apparatuses, such as desktop computers,televisions (TVs), outdoor billboards, display apparatuses forexhibition, and the like. In these display apparatuses, it is common touse pad terminals on a display substrate and driving terminals on adriver. The display substrate may then be electrically connected to thedriver by connecting the pad terminals to the driving terminals.

Often, an anisotropic conductive film is interposed between each of thepad terminals and each of the driving terminals so that each of the padterminals and each of the driving terminals can be coupled to eachother. However, the use of this anisotropic conductive film may renderthe connection between the pad terminals and the driving terminalselectrically unstably.

SUMMARY

Exemplary embodiments of the present invention provide displayapparatuses in which there is a stable electrical coupling between eachpad terminal and each driving terminal. Exemplary embodiments of thepresent invention further provide methods of manufacturing displayapparatuses such as these.

A display apparatus includes a display panel comprising a displaysubstrate on which a plurality of pad terminals is disposed, and adriving unit comprising a plurality of driving terminals electricallyconnected to the plurality of pad terminals. Each of the plurality ofpad terminals includes a stepped groove that faces a correspondingdriving terminal of the plurality of driving terminals or each of theplurality of pad terminals includes an opening hole that faces thecorresponding driving terminal of the plurality of driving terminals.

A display apparatus includes a display panel including a displaysubstrate. A plurality of pad terminals is disposed on the displaysubstrate. A driving unit includes a plurality of driving terminalselectrically connected to the plurality of pad terminals. Each of theplurality of driving terminals includes a stepped groove partiallypenetrating each of the plurality of driving terminals or an openinghole fully penetrating each of the plurality of driving terminals.

A display apparatus includes a display panel. The display panel includesa display substrate on which a plurality of pad terminals is disposed. Athin film encapsulation (TFE) layer is disposed on the displaysubstrate. A driving unit includes a plurality of driving terminalselectrically connected to the plurality of pad terminals. A firststepped groove partially penetrates each of the plurality of padterminals or a first opening hole fully penetrates each of the pluralityof pad terminals. Each of the plurality of driving terminals includes asecond stepped groove partially penetrating each of the plurality ofdriving terminals or a second opening hole fully penetrating each of theplurality of driving terminals.

A method of manufacturing a display apparatus includes forming a steppedgroove partially penetrating a pad terminal, forming a stepped groovepartially penetrating a driving terminal, forming an opening hole fullypenetrating the pad terminal, or forming an opening hole fullypenetrating the driving terminal. The pad terminal and the drivingterminal contact each other. Pressure is applied to the pad terminal orthe driving terminal to squeeze the pad terminal and the drivingterminal together. Part of the pad terminal and part of the drivingterminal are inserted into the stepped groove or the opening hole formedin the pad terminal or the driving terminal. The pad terminal and thedriving terminal are vibrated. The pad terminal and the driving terminalare connected to each other using ultrasound bonding, while the padterminal and the driving terminal are being vibrated. A connectionportion that electrically connects the pad terminal and the drivingterminal is formed.

An electronic device includes a display apparatus. The display apparatusincludes a display panel having at least one pad terminal disposedthereon. A display driver has at least one driving terminal disposedthereon. The driving terminal is connected to the pad terminal. A firstcutout is formed in the pad terminal or a second cutout is formed in thedriving terminal. A connection portion is disposed between the padterminal and the driving terminal. The connection portion includes amixing of a first material from the pad terminal and a second materialfrom the driving terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a plan view of a display apparatus according to an exemplaryembodiment of the present invention;

FIG. 2 is a cross-sectional view of the display apparatus illustrated inFIG. 1;

FIG. 3 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention;

FIG. 4 is a plan view of one pad terminal of FIG. 3;

FIG. 5 is a perspective view of part of the pad terminal of FIG. 4;

FIG. 6 is a plan view of a modified example of the pad terminal of FIG.4;

FIG. 7 is a perspective view of part of the pad terminal of FIG. 6;

FIG. 8 is a cross-sectional view taken along line A-A of FIG. 4, whichshows a driving terminal connected onto the pad terminal;

FIG. 9 is a cross-sectional view taken along line B-B of FIG. 4, whichshows the driving terminal connected to the pad terminal;

FIG. 10 is a cross-sectional view taken along line C-C of FIG. 4, whichshows the driving terminal connected to the pad terminal;

FIG. 11 is a cross-sectional view of a modified example of FIG. 9;

FIG. 12 is a cross-sectional view of the pressurized driving terminaland pad terminal of FIG. 11;

FIG. 13 is a cross-sectional view of a modified example of FIG. 10;

FIG. 14 is a cross-sectional view of a modified example of FIG. 10;

FIG. 15 is a cross-sectional view of a modified example of FIG. 10;

FIG. 16 is a cross-sectional view of a modified example of FIG. 9;

FIG. 17 is a cross-sectional view of a modified example of FIG. 9;

FIG. 18 is a cross-sectional view of a modified example of FIG. 10;

FIG. 19 is a cross-sectional view of a modified example of FIG. 10;

FIG. 20 is a cross-sectional view of a modified example of FIG. 10;

FIG. 21 is a cross-sectional view of a modified example of FIG. 10;

FIG. 22 is a plan view of a modified example of the pad terminal of FIG.4; and

FIG. 23 is a plan view of a modified example of the pad terminal of FIG.4.

DETAILED DESCRIPTION

In describing exemplary embodiments of the present disclosureillustrated in the drawings, specific terminology is employed for sakeof clarity. However, the present disclosure is not intended to belimited to the specific terminology so selected, and it is to beunderstood that each specific element includes all technical equivalentswhich operate in a similar manner.

While such terms as “first,” “second,” etc., in the followingembodiments may be used to describe various components, these componentsshould not be limited by these terms. These terms are only used todistinguish one component from another.

Sizes of elements in the drawings may be exaggerated or reduced forconvenience of explanation.

Exemplary embodiments of the present invention will be described belowin more detail with reference to the accompanying drawings. In thefigures, elements having the same reference numeral may be similar to oridentical to each other.

FIG. 1 is a plan view of a display apparatus according to an exemplaryembodiment of the present invention, FIG. 2 is a cross-sectional view ofthe display apparatus illustrated in FIG. 1, and FIG. 4 is a plan viewof one pad terminal of FIG. 3.

Referring to FIGS. 1 and 2, a display apparatus 100 includes a displaypanel 110. According to an exemplary embodiment of the presentinvention, the display apparatus 100 may be an organic light emittingdisplay device (OLED). However, the display apparatus 100 is not limitedthereto and may be a liquid crystal display (LCD), a field emissiondisplay (FED), an electronic paper display (EPD), or any other form ofdisplay.

The display panel 110 includes a display substrate 120 having aplurality of devices and a thin film encapsulation (TFE) layer 130disposed on the display substrate 120. A plurality of thin filmtransistors (TFTs) and a plurality of light-emitting devices connectedto the plurality of TFTs may be disposed on the display substrate 120. Afunctional film 140, such as a polarizing plate, a touch screen, or acover window, may be disposed on the TFE layer 130.

An active area AA 111 and an inactive area IAA 112 may be disposed onthe display panel 110. The active area AA 111 may display an image. Theinactive area IAA 112 may surround the active area AA 111.

The TFE layer 130 may cover the active area AA 111.

A bending area BA 413, in which the display panel 110 is foldable in onedirection, may be disposed within the inactive area IAA 112. A pad areaPA may extend beyond the bending area BA and may also be disposed withinthe inactive area IAA 112. However, exemplary embodiments of the presentinvention are not limited thereto, and the bending area BA mayalternatively be formed within the active area AA 111. However,hereinafter, for convenience of explanation, the case in which thebending area BA is formed within the inactive area IAA 112 will bedescribed.

The display panel 110 may be folded in one direction along a bendingline BL that is within the bending area BA. However, exemplaryembodiments of the present invention are not limited thereto, and theactive area AA 111 land the pad area PA may be connected to each otherwithout the existence of the bending area BA. For example, the displaypanel 110 may also be rigid and no bending line BL might be present.However, hereinafter, for convenience of explanation, the display panel110 will be described herein as being foldable along the bending lineBL.

The pad area PA may be disposed at one edge of the display substrate120. A plurality of pad terminals 150 may be disposed within the padarea PA. The plurality of pad terminals 150 may be spaced apart fromeach other in both the X-axis direction and the Y-axis direction of thedisplay substrate 120. The pad terminals 150 may be connected to awiring 113 that extends from the active area AA 111.

The plurality of pad terminals 150 may be electrically connected to adriver 160.

The driver 160 may include a driving circuit and the driver 160 may be achip on plastic (COP). However, the driver 160 is not limited thereto.For example, the driver 160 may be a chip on film (COF) or a chip onglass (COG).

The driver 160 includes a flexible film 170 on which a circuit wiring ispatterned, a driving integrated circuit (IC) 180 disposed on the displaysubstrate 120, and a plurality of driving terminals 190 disposed underthe driving IC 180. The flexible film 170 and the driving IC 180 may beelectrically connected to each other, for example, via the displaysubstrate 120.

The flexible film 170 may be electrically connected to a circuit board200. The circuit board 200 may be a flexible printed circuit board(FPCB).

The pad terminals of the plurality of pad terminals 150 may beelectrically connected to corresponding driving terminals of theplurality of driving terminals 190. For example, each of the pluralityof pad terminals 150 may be directly connected to corresponding drivingterminals.

For example, the plurality of pad terminals 150 (see 420 c of FIG. 8)and the plurality of driving terminals 190 (see 540 of FIG. 8) may beconnected to one another via a connection portion (see CP of FIG. 8).The connection portion CP is a layer that is formed by ultrasonicbonding the pad terminals 150 and the driving terminals 190 to eachother. Part of the adjacent pad terminals 150 and part of the drivingterminals 190 are diffused toward each other during the ultrasoundbonding process and are thereby coupled to each other. A detailedcoupling structure of the pad terminals 150 and the driving terminal 190will be described below with reference to FIGS. 8 through 21.

FIG. 3 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention, and FIG. 4 is a plan viewillustrating a pad terminal of FIG. 3.

Referring to FIG. 3, a display panel 300 includes a display substrate301 and a TFE layer 317. According to an exemplary embodiment of thepresent invention, the display panel 300 may be an organic lightemitting display (OLED) panel.

A display area DA is disposed in the active area AA 111 of the displaysubstrate 301 and a pad area PA is disposed in the inactive area IAA 112of the display substrate 301.

The display substrate 301 may be a flexible glass substrate, a flexiblepolymer substrate, a rigid glass substrate, or a rigid polymersubstrate. The display substrate 301 may be transparent,semitransparent, or opaque.

A barrier layer 302 may be disposed on the display substrate 301. Thebarrier layer 302 may cover a top surface of the display substrate 301.The barrier layer 302 may either be an organic layer or an inorganiclayer. The barrier layer 302 may either include a single layer or mayinclude multiple layers.

At least one TFT may be disposed in the display area DA.

A semiconductor active layer 303 may be disposed on the barrier layer302. The semiconductor active layer 303 includes a source area 304 and adrain area 305, which may be formed by doping N-type impurity ions orP-type impurity ions into the semiconductor active layer 303. A channelregion 306, into which no impurities are doped, may be formed betweenthe source area 304 and the drain area 305. The semiconductor activelayer 303 may include an organic semiconductor, an inorganicsemiconductor, or amorphous silicon. According to an exemplaryembodiment of the present invention, the semiconductor active layer 303may include an oxide semiconductor.

A gate insulating layer 307 may be deposited onto the semiconductoractive layer 303. The gate insulating layer 307 may either be an organiclayer or inorganic layer. The gate insulating layer 307 may includeeither a single layer or multiple layers.

A gate electrode 308 may be disposed on the gate insulating layer 307.The gate electrode 308 may include an electrically conductive metal. Forexample, the gate electrode 308 may include molybdenum (Mo), aluminum(Al), copper (Cu), and/or titanium (Ti). The gate electrode 308 mayinclude either a single layer or multiple layers.

An interlayer insulating layer 309 may be disposed on the gate electrode308. The interlayer insulating layer 309 may either be an organic layeror an inorganic layer.

A source electrode 310 and a drain electrode 311 may be disposed on theinterlayer insulating layer 309. Contact holes may be formed by removingpart of the gate insulating layer 307 and part of the interlayerinsulating layer 309. The source electrode 310 may be electricallyconnected to the source area 304 through one of the contact holes, andthe drain electrode 311 may be electrically connected to the drain area305 through another of the contact holes.

The source electrode 310 and the drain electrode 311 may be formed of aconductive metal. For example, the source electrode 310 and the drainelectrode 311 may each include Mo, Al, Cu, and/or Ti. The sourceelectrode 310 and the drain electrode 311 may each include either asingle layer or multiple layers. For example, the source electrode 310and the drain electrode 311 may each have a structure in which Ti/A/Tiare stacked.

A protective layer 312 may be disposed on the source electrode 310 andthe drain electrode 311. The protective layer 312 may either be anorganic layer or inorganic layer. The protective layer 312 may be apassivation layer or a planarization layer. However, the passivationlayer or the planarization layer may be omitted.

The TFT may be electrically connected to the OLED.

The OLED may be disposed on the protective layer 312. The OLED includesa first electrode 313, an intermediate layer 314, and a second electrode315. The intermediate layer 314 may be disposed between the first andsecond electrodes 313 and 315.

The first electrode 313 serves as an anode and may be formed of variousconductive materials. The first electrode 313 may be either atransparent electrode or a reflective electrode. For example, when thefirst electrode 313 is a transparent electrode, the first electrode 313includes a transparent conductive layer. When the first electrode 313 isa reflective electrode, the first electrode 313 includes a reflectivelayer and a transparent conductive layer disposed on the reflectivelayer. According to an exemplary embodiment of the present invention,the first electrode 313 may have a structure in which ITO/Ag/ITO arestacked.

A pixel defining layer (PDL) 316 may be disposed on the protective layer312. The PDL 316 may cover part of the first electrode 313. The PDL 316may define an emission area of each of a plurality of sub-pixels bysurrounding edges of the first electrode 313. The first electrode 313may be patterned in each of the sub-pixels. The PDL 316 may either be anorganic layer or an inorganic layer. The PDL 316 may include either asingle layer or multiple layers.

The intermediate layer 314 may be disposed in an area of the PDL 316that has been exposed by etching. The intermediate layer 314 may beformed by a deposition process.

The intermediate layer 314 may include an organic emission layer.

According to an exemplary embodiment of the present invention, theintermediate layer 314 includes a hole injection layer (HIL), a holetransport layer (HTL), an electron transport layer (ETL), and/or anelectron injection layer (EIL), as well as an organic emission layer.

According to an exemplary embodiment of the present invention, theintermediate layer 314 may include an organic emission layer and mayfurther include various other functional layers.

The second electrode 315 may be disposed on the intermediate layer 314.

The second electrode 315 may function as a cathode. The second electrode315 may either be a transparent electrode or a reflective electrode. Forexample, when the second electrode 315 is a transparent electrode, thesecond electrode 315 includes a metal layer and a transparent conductivelayer disposed on the metal layer. When the second electrode 315 is areflective electrode, the second electrode 315 includes a metal layer.

According to an exemplary embodiment of the present invention, aplurality of sub-pixels may be formed on the display substrate 301. Forexample, red, green, and blue, or red, green, blue, and white sub-pixelsmay be included. However, embodiments of the present invention are notlimited thereto.

The TFE layer 317 may cover the OLED.

First and second inorganic layers 318 and 319 and an organic layer 320may be alternately stacked on the TFE layer 317. For example, the firstinorganic layer 318, the organic layer 320, and the second inorganiclayer 319 may be sequentially stacked on the OLED. There may be variousmodified examples of a stacked structure of the inorganic layers 318 and319 and the organic layer 320 on the TFE layer 317.

A touch screen 340 may be installed on the TFE layer 317. According toan exemplary embodiment of the present invention, the touch screen 340may be an electrostatic capacitive type touch screen. For example, abase layer may be disposed on the TFE layer 317. A plurality of touchelectrode wirings may be disposed on the base layer. According to anexemplary embodiment of the present invention, the plurality of touchelectrode wirings may have a structure in which Ti/Al/Ti are stacked.According to an exemplary embodiment of the present invention, the baselayer may be omitted. The touch electrode wirings may cover a touchelectrode insulating layer. The touch electrode insulating layer may bean organic layer or an inorganic layer.

A first insulating layer 331 may be disposed in the pad area PA of thedisplay substrate 301. The first insulating layer 331 may be disposed onthe same layer as the barrier layer 302. For example, the firstinsulating layer 331 may be formed of the same material and by the sameprocess as the barrier layer 302.

A second insulating layer 332 may be disposed on the first insulatinglayer 331. The second insulating layer 331 may be disposed on the samelayer as the gate insulating layer 307. For example, the secondinsulating layer 332 may be formed of the same material and by the sameprocess as the gate insulating layer 307.

First conductive layers 410 disposed on each pad terminal 401 may bedisposed on the second insulating layer 332 as each other. The firstconductive layers 410 may be electrically connected to a wiring 325 thatextends from the display area DA. The first conductive layers 410 may bedisposed on the same layer as the gate electrode 308. For example, eachof the first conductive layers 410 may be formed of the same materialand in the same process the gate electrode 308. The first conductivelayers 410 may be spaced apart from one another in one direction of thedisplay substrate 301.

A third insulating layer 333 may be disposed on each of the firstconductive layers 410. The third insulating layer 333 may be disposed onthe same layer as the interlayer insulating layer 309. The thirdinsulating layer 333 may be formed of the same material and in the sameprocess as the interlayer insulating layer 309. According to anexemplary embodiment of the present invention, the third insulatinglayer 333 may either be an organic layer or an inorganic layer.

The third insulating layer 333 may cover at least part of the firstconductive layer 410. By removing part of the third insulating layer333, a contact hole 431 may be formed in the first conductive layer 410.A top surface of the first conductive layer 410 may be exposed in aregion of the first conductive layer 410 in which the contact hole 431is formed.

Second conductive layers 420 may be disposed on the first conductivelayers 410. The second conductive layers 420 may be disposed in anisland form on the first conductive layers 410. According to anexemplary embodiment of the present invention, the second conductivelayers 420 may be electrically connected to the wiring 325 that extendsfrom the display area DA.

The second conductive layers 420 may be disposed on the same layer asboth the source electrode 310 and the drain electrode 311. For example,the second conductive layer 420 may be formed of the same material andin the same process as the source electrode 310 and the drain electrode311. According to an exemplary embodiment of the present invention, thesecond conductive layers 420 may include a plurality of layers in whichlayers of Al and/or Ti are stacked. The stack structure of the secondconductive layer 420 may be differently composed, for example, thesecond conductive layer 420 may include stacked layers such as Al/Ti/Alor Ti/Al/Ti.

Referring to FIGS. 3 and 4, the second conductive layer 420 may beelectrically connected to the first conductive layer 410 via the contacthole 431. For example, the second conductive layer 420 may beelectrically connected to the first conductive layer 410 in a region inthe third insulating layer 333 is not disposed. The first conductivelayer 410 and the second conductive layer 420 may form a contact portionCNT in a region in which the contact hole 431 is formed.

The second conductive layer 420 may extend over a region of the firstconductive layer 410 exposed through the contact hole 431 of FIG. 4 andthe second conductive layer 420 may extend partially over the thirdinsulating layer 333 where the third insulating layer 333 covers thefirst conductive layer 410 (e.g., as shown in FIG. 8).

As illustrated in FIG. 4, the size of the second conductive layer 420may be greater than the size of the first conductive layer 410. Forexample, the second conductive layer 420 may have the size sufficientlylong so as to entirely cover the first conductive layer 410. The firstconductive layer 410 and the second conductive layer 420 might not beelectrically connected to each other in all regions but rather, they maybe connected to each other through the contact hole 431 where part ofthe third insulating layer 333 is removed. Part of the second conductivelayer 420 may be disposed in the exposed region of the first conductivelayer 410 through the contact hole 431, and another part of the secondconductive layer 420 may be disposed on the third insulating layer 333.

As will be described in greater detail below, each of the drivingterminals 540 may be electrically connected to a corresponding padterminal 401 (see FIG. 8). A circuit pattern 520 may be disposed under adriving IC 510. An insulating layer 530 may cover part of the circuitpattern 520. Each of the driving terminals 540 may be electricallyconnected to the circuit pattern 520. Each of the driving terminals 540includes a bump. The driving terminal 540 may include gold (Au) nickel(Ni), and/or tin (Sn).

Each of the driving terminals 540 may extend to a region in which thefirst conductive layer 410 and the second conductive layer 420 of FIG. 8are electrically connected to each other and each of the drivingterminals 540 may extend to a region in which the first conductive layer410 and the second conductive layer 420 of FIG. 10 are spaced apart fromeach other and the third insulating layer 333 is disposed therebetween.

According to an exemplary embodiment of the present invention, the firstconductive layer 410 and the second conductive layer 420 may be disposedon the same layers as other metal layers disposed on the displaysubstrate 301 of FIG. 3. These other metal layers may include the firstelectrode 313, the second electrode 315, and/or the touch electrode 322,as well as the gate electrode 308, the source electrode 310, and/or thedrain electrode 311.

According to an exemplary embodiment of the present invention, the thirdinsulating layer 333 may be disposed on the same layer as an insulatinglayer, such as the gate insulating layer 307, the protective layer 312,the PDL 316, the TFE layer 317, and/or the touch electrode insulatinglayers 323 and 324, which are patterned on the display substrate 301 ofFIG. 3, as well as the interlayer insulating layer 309.

Hereinafter, the pad terminal 400 and the driving terminal 540 will bedescribed in detail with reference to FIGS. 4 through 23.

FIG. 5 is a perspective view of part of the pad terminal of FIG. 4. FIG.6 is a plan view of one modified example of the pad terminal of FIG. 4.FIG. 7 is a perspective view of part of the pad terminal of FIG. 6. FIG.8 is a cross-sectional view taken along line A-A of FIG. 4, which showsa driving terminal connected onto the pad terminal. FIG. 9 is across-sectional view taken along line B-B of FIG. 4, which shows thedriving terminal connected to the pad terminal. FIG. 10 is across-sectional view taken along line C-C of FIG. 4, which shows thedriving terminal connected to the pad terminal. FIG. 11 is across-sectional view of one modified example of FIG. 9. FIG. 12 is across-sectional view of the pressurized driving terminal and padterminal of FIG. 11.

Referring to FIGS. 3 and 4, a plurality of pad terminals 400 may bedisposed in the pad area PA and may be electrically connected to thedriving terminal 540. Each pad terminal 401 of the plurality of padterminals 400 may be spaced apart from one another in one direction ofthe display substrate 301.

For example, referring to FIGS. 4 through 7, each pad terminal 401 mayinclude either a stepped groove 421 a partially penetrating a surfacefacing each of the driving terminals 540 or an opening hole 421 b thatfully penetrates each pad terminal 401. For convenience of explanation,in FIGS. 4 and 5, only the stepped groove 421 a is shown as being formedin each pad terminal 401, and in FIGS. 6 and 7, only the opening hole421 b is shown as being formed in each pad terminal 401. However,embodiments of the present invention are not limited thereto. Forexample, each pad terminal 401 may include both the stepped groove 421 aand the opening hole 421 b.

Referring to FIG. 8, each pad terminal 401 and the driving terminal 540may be electrically connected to each other via the connection portionCP. As described above, each pad terminal 401 and the driving terminal540 may be coupled to each other by performing ultrasound bonding.Through ultrasound bonding, surfaces on which each pad terminal 401 andthe driving terminal 540 contact each other may be softened and diffusedand thus the surfaces may be coupled to each other.

Thus, the connection portion CP may be formed as a mixed layer in whichpart of each pad terminal 401 and part of the driving terminal 540 aremixed with each other. For example, when each pad terminal 401 is formedof Ti and the driving terminal 540 is formed of Au, ultrasound bondingmay create a connection portion CP that includes both Ti and Au.

Meanwhile, a plurality of stepped grooves 421 a and a plurality ofopening holes 421 b may be formed on the entire surface of each padterminal 401. At least part of the plurality of stepped grooves 421 aand the plurality of opening holes 421 b may be shielded by theconnection portion CP.

For example, as described above, each pad terminal 401 and the drivingterminal 540 are connected to each other using ultrasound bonding. Inthis case, ultrasound bonding may be performed on part of the drivingterminal 540 when the part of the driving terminal 540 is inserted intothe stepped groove 421 a or the opening hole 421 b of each pad terminal401. Thus, the connection portion CP formed by connecting each padterminal 401 and the driving terminal 540 using ultrasound bonding mayshield part of the stepped groove 421 a or the opening hole 421 b.

The stepped groove 421 a or the opening hole 421 b may be formed in aregion in which each pad terminal 401 and the driving terminal 540 donot contact each other. In this case, the stepped groove 421 a and theopening hole 421 b might not be shielded by the connection portion CPbut, rather, may remain exposed.

An operation of connecting each pad terminal 401 and the drivingterminal 540 using ultrasound bonding will be described below in detailwith reference to FIG. 12.

Referring back to FIGS. 8 through 12, each pad terminal 401 of theplurality of pad terminals 400 may include a first conductive layer 410and a plurality of second conductive layers 420 (including 420 a, 420 b,and 420 c). The plurality of second conductive layers 420 is disposed onthe first conductive layer 410. Although three, second conductive layers420 a, 420 b, and 420 c are shown in the drawings, the second conductivelayers 420 may alternatively be formed as a single layer. Thus,hereinafter, for convenience of explanation, it is assumed that thesecond conductive layers 420 a, 420 b and 420 c are formed as a singlesecond conductive layer 420, and a structure in which the secondconductive layer 420 is coupled to the driving terminal 540, will bedescribed.

At least part of the first conductive layer 410 and at least part of thesecond conductive layer 420 may be electrically connected to each other.Here, the stepped groove 421 a and the opening hole 421 b of each padterminal 401 may be formed in the second conductive layer 420. Forexample, the stepped groove 421 a and the opening hole 421 b may beformed within one of the plurality of second conductive layers 420 a,420 b, and 420 c at an upper side facing the driving terminal 540.

The driving terminal 540 illustrated in FIGS. 8 through 12 may include aprotrusion portion 540 p that protrudes toward each pad terminal 401 atan edge of one surface of the driving terminal 540 facing each padterminal 401. The protrusion portion 540 p may contact the respectivepad terminal 401 and a concave portion 540 c that is inserted in adirection opposite to a direction toward each pad terminal 401 in thecenter of the driving terminal 540 and spaced apart from the respectivepad terminal 401.

However, embodiments of the present invention are not limited thereto.For example, the protrusion portion 540 p of the driving terminal 540may be formed in the center of the driving terminal 540, andalternatively, the concave portion 540 c may be formed at an edge of onesurface of the driving terminal 540 facing each pad terminal 401. Thisconfiguration will be described in greater detail below with referenceto FIGS. 13 through 15.

According to the above-described configuration, as illustrated in FIG.9, when the protrusion portion 540 p of the driving terminal 540 isformed at an edge of one surface of the driving terminal 540 facing eachpad terminal 401, the connection portion (CP of FIG. 8) may be formed atthe edge of the driving terminal 540 of each pad terminal 401. At leastpart of the stepped groove (421 a of FIG. 9) and at least part of theopening hole (421 b of FIG. 11) may also be formed at edges of each padterminal 401 and the driving terminal 540.

Here, the connection portion CP is shown in FIG. 8. FIGS. 9 and 11 showa state before each pad terminal 401 and the driving terminal 540 areultrasonic-bonded, and therefore, before the connection portion CP isformed. A process in which the connection portion CP is formed will bedescribed in detail below with reference to FIG. 12.

FIG. 12 illustrates part of a process of manufacturing the displayapparatus 100 in which each pad terminal 401 and the driving terminal540 are coupled to each other. For example, FIG. 12 shows a state aftera process of forming an opening hole 421 b in the second conductivelayer 420 of each pad terminal 401 has been performed, and a state inwhich each pad terminal 401 and the driving terminal 540 contact eachother and are pressurized in a first direction (a direction of arrows)in which each pad terminal 401 and the driving terminal 540 are close toeach other. Pressure may be applied to bring each pad terminal 401 intoclose contact with the driving terminal 540.

However, embodiments of the present invention are not limited to theabove-described configuration. The opening hole 421 b may be formed inthe driving terminal 540, as shown in FIGS. 16 through 19, as well as ineach pad terminal 401. Also, as illustrated in FIGS. 20 and 21, theopening hole 421 b may be formed in each pad terminal 401 and in thedriving terminal 540. Also, the stepped groove 421 a of FIG. 9, as wellas the opening hole 421 b, may also be formed in each pad terminal 401and/or the driving terminal 540.

Hereinafter, as illustrated in FIG. 12, a process in which each padterminal 401 and the driving terminal 540 are coupled to each other willbe described based on a case where the opening hole 421 b is formed inonly the second conductive layer 420 of each pad terminal 401.

In order to couple each pad terminal 401 and the driving terminal 540 toeach other, as shown in FIG. 12, when each pad terminal 401 and thedriving terminal 540 are pressurized in the first direction (see arrows)in which each pad terminal 401 and the driving terminal 540 are close toeach other, part of the driving terminal 540 may be inserted into theopening hole 421 b of the second conductive layer 420. For example, whenthe driving terminal 540 is pressurized toward each pad terminal 401,the driving terminal 540 may be moved lower than a shape of the drivingterminal 540 before being pressurized (see the X-axis of FIG. 12). Thisis because part of the driving terminal 540 may be inserted into a spaceof the opening hole 421 b.

In this state, each pad terminal 401 and the driving terminal 540 may bevibrated in a second direction that crosses the first direction (forexample, the first direction may be a width direction and the seconddirection may be a height directions of FIG. 4). Also, each pad terminal401 and the driving terminal 540 may be electrically coupled to eachother using an ultrasound bonding process.

In this case, part of the driving terminal 540 inserted into the openinghole 421 b and the second conductive layer 420 of each pad terminal 401may be mixed with each other and the connection portion CP may be formedthereby. The connection portion CP may be formed to fully fill theopening hole 421 b. Alternatively, the connection portion CP may beformed to only partially fill the opening hole 421 b so that theconnection portion CP may have a structure for shielding the openinghole 421 b from the outside.

In general, when each pad terminal 401 and the driving terminal 540 areconnected to each other using ultrasound bonding, a slip phenomenon mayoccur at an interface between each pad terminal 401 and the drivingterminal 540. When the slip phenomenon occurs at the interface betweeneach pad terminal 401 and the driving terminal 540, each pad terminal401 might not be properly aligned with the driving terminal 540 and aconnection defect in which each pad terminal 401 and the drivingterminal 540 are not electrically connected to each other, may occur.

Where each pad terminal 401 and the driving terminal 540 have the abovestructure, each pad terminal 401 and the driving terminal 540 may bevibrated when part of the driving terminal 540 is inserted into thestepped groove 421 a or the opening hole 421 b formed in each padterminal 401 such that friction between each pad terminal 401 and thedriving terminal 540 may be maximized.

Thus, when the stepped groove 421 a or the opening hole 421 b is formedin each pad terminal 401 at the connection portion CP where each padterminal 401 and the driving terminal 540 are connected to each other, africtional force between each pad terminal 401 and the driving terminal540 is maximized so that a slip phenomenon occurring between each padterminal 401 and the driving terminal 540 may be minimized.

FIG. 13 is a cross-sectional view of a modified example of FIG. 10. FIG.14 is a cross-sectional view of a modified example of FIG. 10. FIG. 15is a cross-sectional view of a modified example of FIG. 10.

Referring to FIG. 13, the protrusion portion 540 p of the drivingterminal 540 may also be formed in the center of the driving terminal540, as described above. In this case, a connection portion may beformed in the center of each pad terminal 401 and the driving terminal540, and at least part of the stepped groove 421 a and the opening hole421 b may also be formed in the center of each pad terminal 401 and thedriving terminal 540.

Referring to FIG. 14, the stepped groove 421 a may be formed in thecenter of the second conductive layer 420 of each pad terminal 401 thatcontacts the protrusion portion 540 p. Thus, when an ultrasound bondingprocess of each pad terminal 401 and the driving terminal 540 isperformed, part of the driving terminal 540 is inserted into the steppedgroove 421 a. In this state, ultrasound bonding is performed so thateach pad terminal 401 and the driving terminal 540 may be electricallyconnected to each other through the connection portion.

Referring to FIG. 15, the opening hole 421 b may also be formed in thecenter of the second conductive layer 420 of each pad terminal 401 thatcontacts the protrusion portion 540 p. Thus, when an ultrasound bondingprocess of each pad terminal 401 and the driving terminal 540 isperformed, part of the driving terminal 540 is inserted into the openinghole 421 b. In this case, ultrasound bonding is performed so that eachpad terminal 401 and the driving terminal 540 may be electricallyconnected to each other through the connection portion.

Meanwhile, the stepped groove 421 a and the opening hole 421 b may alsobe formed in the driving terminal 540, as well as in each pad terminal401. This structure will be described below with reference to FIGS. 16through 19.

FIG. 16 is a cross-sectional view of a modified example of FIG. 9. FIG.17 is a cross-sectional view of a modified example of FIG. 9. FIG. 18 isa cross-sectional view of a modified example of FIG. 10. FIG. 19 is across-sectional view of a modified example of FIG. 10.

Referring to FIG. 16, the protrusion portion 540 p of the drivingterminal 540 may be formed at an edge of one surface of the drivingterminal 540 that faces each pad terminal 401. A stepped groove 541 amay be formed in the protrusion portion 540 p. The stepped groove 541 ashown in FIG. 16 is not enlarged, as shown in FIG. 9. However, like inthe stepped groove 421 a of FIG. 9, the stepped groove 541 a may beformed in part of the protrusion portion 540 p, and the other part ofthe protrusion portion 540 p may contact the second conductive layer 420of each pad terminal 401.

Through this structure, when the ultrasound bonding process of each padterminal 401 and the driving terminal 540 is performed, part of thesecond conductive layer 420 may be inserted into the stepped groove 541a. In this state, the ultrasound bonding process is performed so that aconnection portion (may be formed and may electrically connect each padterminal 401 to the driving terminal 540.

Meanwhile, referring to FIG. 17, an opening hole 541 b may also beformed in the protrusion portion 540 p at the edge of one surface of thedriving terminal 540 that faces each pad terminal 401. Thus, when theultrasound bonding process of each pad terminal 401 and the drivingterminal 540 is performed, part of the second conductive layer 420 maybe inserted into the opening hole 541 b. In this case, the ultrasoundbonding process is performed so that a connection portion may be formedto electrically connect each pad terminal 401 to the driving terminal540.

Referring to FIG. 18, the protrusion portion 540 p of the drivingterminal 540 may also be formed in the center of the driving terminal540. The stepped groove 541 a may be formed in the protrusion portion540 p in the center of the driving terminal 540. Through this structure,when the ultrasound bonding process of each pad terminal 401 and thedriving terminal 540 is performed, part of the second conductive layer420 may be inserted into the stepped groove 541 a. In this state, whenthe ultrasound bonding process of each pad terminal 401 and the drivingterminal 540 is performed, part of the second conductive layer 420 maybe inserted into the stepped groove 541 a. In this state, the ultrasoundbonding process is performed so that a connection portion may be formedto electrically connect each pad terminal 401 to the driving terminal540.

Referring to FIG. 19, the opening hole 541 b may also be formed in theprotrusion portion 540 p formed in the center of the driving terminal540. Through this structure, when the ultrasound bonding process of eachpad terminal 401 and the driving terminal 540 is performed, part of thesecond conductive layer 420 may be inserted into the opening hole 541 b.In this state, the ultrasound bonding process is performed so that aconnection portion may be formed to electrically connect each padterminal 401 to the driving terminal 540.

The stepped groove 421 a and the opening hole 421 b may besimultaneously formed in each pad terminal 401 and the driving terminal540. This structure will be descried below with reference to FIGS. 20and 21.

FIG. 20 is a cross-sectional view of a modified example of FIG. 10, andFIG. 21 is a cross-sectional view of a modified example of FIG. 10.

Referring to FIG. 20, a second stepped groove 541 a may be formed in theprotrusion portion 540 p at the edge of one surface of the drivingterminal 540 that faces each pad terminal 401, and simultaneously, afirst stepped groove 421 a may be formed in the second conductive layer420 of each pad terminal 401 that contacts the protrusion portion 540 p.Here, a first stepped groove 421 a and the second stepped groove 541 amay be disposed to project in opposite directions with respect to eachother.

Trough this structure, when the ultrasound bonding process of each padterminal 401 and the driving terminal 540 is performed, due to pressureapplied to each pad terminal 401 and the driving terminal 540, part ofeach pad terminal 401 may be inserted into the second stepped groove 541a formed in the driving terminal 540, and simultaneously, part of thedriving terminal 540 may be inserted into the first stepped groove 421 aformed in each pad terminal 401. In this state, the ultrasound bondingprocess may be performed to form a connection portion electricallyconnecting each pad terminal 401 and the driving terminal 540.

Meanwhile, referring to FIG. 21, a second opening hole 541 b may beformed in the protrusion portion 540 p at the edge of one surface of thedriving terminal 540 that faces each pad terminal 401, andsimultaneously, a first opening hole 421 b may be formed in the secondconductive layer 420 of each pad terminal 401 that contacts theprotrusion portion 540 p. Here, the first opening hole 421 b and thesecond opening hole 541 b may be disposed to project in oppositedirections.

Through this structure, when the ultrasound bonding process of each padterminal 401 and the driving terminal 540 is performed, due to pressureapplied to each pad terminal 401 and the driving terminal 540, part ofeach pad terminal 401 may be inserted into the second opening hole 541 bformed in the driving terminal 540, and simultaneously, part of thedriving terminal 540 may be inserted into the first opening hole 421 bformed in each pad terminal 401. In this state, the ultrasound bondingprocess may be performed so that a connection portion may be formed toelectrically connect each pad terminal 401 to the driving terminal 540.

When one or both of the stepped groove 421 a and the first opening hole421 b and one or both of the second stepped groove 541 a and the secondopening hole 541 b are respectively formed in each pad terminal 401 andthe driving terminal 540, as illustrated in FIGS. 20 and 21, the centerof the driving terminal 540 may also be formed as a concave portion 540c, and the edge of one surface of the driving terminal 540 that faceseach pad terminal 401 may also be formed as the protrusion portion 540p. However, embodiments of the present invention are not limitedthereto.

For example, as illustrated in FIGS. 13 through 15 or FIGS. 18 and 19,in a state in which the center of the driving terminal 540 is formed asthe protrusion portion 540 p and the edge of one surface of the drivingterminal 540 that faces each pad terminal 401 is formed as the concaveportion 540 c, one or both of the stepped groove 421 a and the openinghole 421 b may be formed in the center of each pad terminal 401. Also,one or both of the stepped groove 541 a and the opening hole 541 b mayalso be formed in a protrusion portion (not shown) of the drivingterminal 540.

Various shapes of second conductive layers 1420 and 2420 of each padterminal 1400 will be described with reference to FIGS. 22 and 23.

FIG. 22 is a plan view of a modified example of each pad terminal 401 ofFIG. 4, and FIG. 23 is a plan view of a modified example of each padterminal 401 of FIG. 4.

Referring to FIG. 22, according to an exemplary embodiment of thepresent invention, the second conductive layer 1420 of each pad terminal1400 may include a plurality of circular opening holes 1421. FIG. 22shows the opening holes 1421 that pass through the second conductivelayer 1420. However, embodiments of the present invention are notlimited thereto. The opening holes 1421 may also be formed as steppedgrooves 1421 spaced apart from a surface facing the driving terminal 540by a predetermined distance.

Through this structure, part of the driving terminal 540 that contactsthe second conductive layer 1420 may be inserted into each of theopening holes 1421. Through this structure, in a process of coupling thepad terminal 1400 and the driving terminal 540 using ultrasound bonding,due to part of the driving terminal 540 inserted into the opening hole1421, the pad terminal 1400 and the driving terminal are engaged witheach other so that friction between the pad terminal 1400 and thedriving terminal 540 may be maximized and slipping may be minimized.

Next, referring to FIG. 23, the second conductive layer 2420 of a padterminal 2400 may also include a plurality of opening holes 2421 formedin both sides of the second conductive layer 2420 at a particular angleof inclination. FIG. 23 shows the opening holes 2421 that pass throughthe second conductive layer 2420, as in FIG. 22. Embodiments of thepresent invention are not limited to this particular structure. Theopening holes 2421 may also be formed as stepped grooves 2421 spacedapart from a surface facing the driving terminal 540 by a predetermineddistance.

Through this structure, although not shown, part of the driving terminal540 that contacts the second conductive layer 1420 may be inserted intothe opening holes 2421. Through this structure, as described above, whenan ultrasound bonding process of the pad terminal 1400 and the drivingterminal 540 is performed, a frictional force between the pad terminal1400 and the driving terminal 540 may be maximized. Thus, a slipphenomenon that may occur between the pad terminal 1400 and the drivingterminal 540 may be minimized.

The second conductive layers 1420 and 2420 of the pad terminals 1400 and2400 illustrated in FIGS. 22 and 23 may be formed in various shapes.Some of these shapes are shown in the drawings and some are not. Asdescribed above, at least one stepped groove, at least one opening hole1421, or at least one opening hole 2421 may be formed in a surfacefacing the driving terminal 540 of each of the second conductive layers1420 and 2420. In this configuration, a frictional force between thedriving terminal 540 and the pad terminal 400 may be optimized for theultrasound bonding process of coupling the driving terminal 540 to thepad terminal 400.

As described above, according to exemplary embodiments of the presentinvention, a display apparatus in which a pad terminal and a drivingterminal can be electrically stably coupled to each other is provided.Additionally, a method of manufacturing the same can be implemented.

It should be understood that while exemplary embodiments of the presentinvention have been described herein, these exemplary embodiments shouldbe considered descriptive and non-limiting. Descriptions of features oraspects within each exemplary embodiment of the present invention shouldbe considered as available for other similar features or aspects inother exemplary embodiments of the present invention.

While one or more exemplary embodiments of the present invention havebeen described herein with reference to the figures, it will beunderstood by those of ordinary skill in the art, that various changesin form and details may be made therein without departing from thespirit and scope of the invention.

What is claimed is:
 1. A display apparatus, comprising: a display panelcomprising a display substrate on which a plurality of pad terminals aredisposed; a thin film encapsulation (TFE) layer disposed on the displaysubstrate; and a driving unit comprising a plurality of drivingterminals electrically connected to the plurality of pad terminals,wherein a first stepped groove partially penetrates each of theplurality of pad terminals or a first opening hole fully penetrates eachof the plurality of pad terminals, and wherein each of the plurality ofdriving terminals comprises a second stepped groove partiallypenetrating each of the plurality of driving terminals or a secondopening hole fully penetrating each of the plurality of drivingterminals.
 2. The display apparatus of claim 1, wherein the firststepped groove and the second stepped groove penetrate their respectiveterminals in opposite directions from each other and the first openinghole and the second opening hole penetrate their respective terminals inopposite directions.
 3. The display apparatus of claim 1, furthercomprising a connection portion that electrically connects the padterminal to the driving terminal, the connection portion including anintermix of a first material from the pad terminal and a second materialfrom the driving terminal.
 4. The display apparatus of claim 3, whereinthe display apparatus further includes a plurality of first steppedgrooves, including the first stepped groove, a plurality of secondstepped grooves, including the second stepped groove, a plurality offirst opening holes, including the first opening hole, and a pluralityof second opening holes, including the second opening hole, wherein atleast part of the plurality of first stepped grooves, at least part ofthe plurality of second stepped grooves, at least part of the pluralityof first opening holes, or at least part of the plurality of secondopening holes are shielded by the connection portion.
 5. The displayapparatus of claim 1, wherein each of the plurality of driving terminalscomprises: a protrusion portion that protrudes in a first direction thatis toward each of the plurality of pad terminals and contacts each ofthe plurality of pad terminals; and a concave portion disposed in asecond direction opposite to the first direction and spaced apart fromeach of the plurality of pad terminals.
 6. The display apparatus ofclaim 5, wherein the protrusion portion is disposed at an edge of onesurface of each of the plurality of driving terminal facing each of theplurality of pad terminals, and the concave portion is disposed in acenter of each of the plurality of driving terminals.
 7. The displayapparatus of claim 5, wherein at least part of the plurality of firststepped grooves and at least part of the plurality of first openingholes are disposed at an edge of one surface of each of the plurality ofdriving terminals, facing each of the plurality of pad terminals, and atleast part of the plurality of second stepped grooves and at least partof the plurality of second opening holes are disposed at an edge of onesurface of each of the plurality of driving terminals, facing each ofthe plurality of pad terminals.
 8. The display apparatus of claim 5,wherein the protrusion portion is disposed in a center of each of theplurality of driving terminals, and the concave portion is disposed atan edge of one surface of each of the plurality of driving terminals,facing each of the plurality of pad terminals.
 9. The display apparatusof claim 5, wherein at least part of the plurality of first steppedgrooves and at least part of the plurality of first opening holes aredisposed in a center of each of the plurality of pad terminals, and atleast part of the plurality of second stepped grooves and at least partof the plurality of second opening holes are disposed in a center ofeach of the plurality of driving terminals.
 10. The display apparatus ofclaim 1, wherein each of the plurality of pad terminals comprises: afirst conductive layer; and a second conductive layer disposed on thefirst conductive layer.
 11. The display apparatus of claim 10, whereinat least one of the first stepped groove and the first opening hole isdisposed on the second conductive layer.
 12. The display apparatus ofclaim 10, wherein a plurality of second conductive layers are provided,and wherein at least one of the first stepped groove and the firstopening hole is disposed on one of the plurality of the secondconductive layers facing each of the plurality of driving terminals. 13.The display apparatus of claim 1, wherein at least part of the firststepped groove is disposed at an angle with respect to an outerperiphery of one surface of each of the plurality of pad terminalsfacing each of the plurality of driving terminals.
 14. The displayapparatus of claim 1, wherein at least part of the second stepped grooveis disposed at an angle with respect to an outer periphery of one sideof each of the plurality of driving terminals facing the plurality ofpad terminals.
 15. The display apparatus of claim 1, wherein the displaypanel comprises: a bent area that is bent in one direction; and a padarea in which the plurality of pad terminals are disposed.
 16. Thedisplay apparatus of claim 1, further comprising a touch screen disposedon the TFE layer.
 17. A display apparatus, comprising: a displaysubstrate on which a plurality of pad terminals are disposed; a thinfilm encapsulation (TFE) layer disposed on the display substrate andconnected to the plurality of pad terminals; a light-emitting elementelectrically connected to the TFE; and a driving unit comprising aplurality of driving terminals electrically connected to the pluralityof pad terminals, wherein a first stepped groove partially penetrateseach of the plurality of pad terminals or a first opening hole fullypenetrates each of the plurality of pad terminals, and wherein each ofthe plurality of driving terminals comprises a second stepped groovepartially penetrating each of the plurality of driving terminals or asecond opening hole fully penetrating each of the plurality of drivingterminals.
 18. The display apparatus of claim 17, further comprising aconnection portion that electrically connects the pad terminal to thedriving terminal, the connection portion including an intermix of afirst material from the pad terminal and a second material from thedriving terminal.
 19. The display apparatus of claim 17, wherein each ofthe plurality of driving terminals comprises: a protrusion portion thatprotrudes in a first direction that is toward each of the plurality ofpad terminals and contacts each of the plurality of pad terminals; and aconcave portion disposed in a second direction opposite to the firstdirection and spaced apart from each of the plurality of pad terminals.20. The display apparatus of claim 19, wherein the protrusion portion isdisposed in one of an outer periphery of one surface of the drivingterminal, facing the pad terminal, and a center of the driving terminal,and wherein the concave portion is disposed in another one of the outerperiphery of the one surface of the driving terminal, facing the padterminal, and the center of the driving terminal.